Crutch tip



W. C. THRO CRUTCH TIP April 13, 1965 Filed Dec. 28. 1961 United States Patent() "ice 3,177,884 Y CRUTCH TIF Wiiliam C. Ihre, 4116A N. Newstead, St. Louis, Mo. Filed Dec. 2S, 1961, Ser. No. 162,763 9 Claims. (Cl. 13S- 54) This invention relates to tips for canes, crutches and the like. The .term crutch is used herein broadly to encompass all such supports which require, or can utilize removable tips.

The desirability of providing a spike-like tip to crutches, for use on snow and ice, or gravelly or other treacherous surfaces, has been recognized for many years. U.S. Patent No. 2,580,295 represents a fairly typical approach to a slution of the problem. The prior artt devices have been ingenious, but something, probably their cost, has evidently prevented .their being widely adopted.

One of the objects of this invention is to provide a crutch tip which is eiective and safe, simple and convenient, easy to manufacture and inexpensive to purchase.

Other `objects will become apparent .to those skilled in the art in the light of the following description and accompanying drawing.

In accordance with this invention, `generally stated, a crutch tip is provided, which is adapted removably to tit the end of a crutch. The crutch tip includes a cup, of resilient material, of a size snugly frictionally to engage the end of the crutch, the cup having a central, axially directed aperture in its bottom wall; an insert mounted in the cup, the insert having a strong crutch-bottom bearing disk of a size a least co-extensive with the bottom o-f the crutch and positioned :below the crutch when the crutch end is inserted in the cup, a bushing depending from the disk, and preferably integral therewith, and extending into the aperture in the bottom wall of the cup, and a spike removably mounted on the bushing. The spike and bushing have complementary, positive acting but manually releasable holding means.

In the preferred embodiment, the bushing has a cylindrical passage, opening downwardly, the defining walls of which are internally threaded, to receive a threaded stud on the spike. The spike is provided with a radially outwardly extending collar, so that, when the spike is tightened, the bottom wall of the cup is clamped between the disk and the spike collar.

The collar on .the spike, therefore, serves several functions. It serves as a kind of lock washer, inhibiting the turning of the spike. This is particularly important when the bushing and spike-coupling means are complementary parts of a bayonet type coupling, but it is also useful in the preferred, threaded type coupling. It also adds rigidity and strength, not only to the spike and insert, but also to the bottom wall of the cup. One of the virtues of this device is that .the spike is rigidly held, with respect to the crutch, even though it is mounted on a cup of resilient material such as rubber. However, different forms of spike, such as a multi-pronged type, may be used.

In the drawing, FIGURE l is a view in perspective of a crutch (cane) equipped withra tip of this invention;

FIGURE 2 is a longitudinal sectional view of one embodiment of tip of this invention mounted on the end of a crutch;

FIGURE 3 is a view in perspective of the spike element of the tip shown in FIGURE 2;

FIGURE 4 is a longitudinal sectional view of another embodiment of tip of this invention with the spike removed, mounted on the end of a crutch;

FIGURE 5 is a longitudinal sectional view of still another embodiment of tip of this invention, with the spike removed, mounted on the end of a crutch;

FIGURE 6 is a fragmentary longitudinal sectional view of still another embodiment of tip of this invention, with 3,177,884 Fatented Apr. I3, 1965 the spike removed, mounted on the end of a crutch especially adapted to use with the tip;

FIGURE 7 is a fragmentary longitudinal sectional view Iof still .another embodiment of this invention, with Ythe spike removed;

FIGURE 8 is a fragmentary longitudinal sectional view of an embodiment of this invention similar to that of FIGURE 2, except for diiferent spike coupling means; and

FIGURE 9 is a view in side elevation showing a moditied spike with three prongs.,

Referring now to the drawing, for illustrative embodiments of this invention, FIGURE l illustrates the tip of this invention in use on a cane lil. In FIGURE 1, the externals ofthe tip, a cup l and a spike 16, are shown.

FIGURE 4 shows a sectional view of the simplest embodiment. In this embodiment, the cup 1 of resilient ma: terial, such as rubber, has an open topped cavity 2 defined by a bottom wall 6 and a side wall 3. The side wall 3 has an inside surface 4 which is substantially cylindrical and an outside sumace 5 which is convergent upwardly, to give the cup 1 the external appearance oi a truncated conc.

The cavity 2 is of such a diameter as snugly frictionally to engage the lower end of the crutch 10, which, in this illustration, is a cane. y The bottom of the cavity 2 is delined .by the heavy bottom wall 6. In this embodiment an aperture 7 centered in the bottom Wall 6, extends axially entirely through the bottom wall 6.

An insert 12, in this embodiment, is made up of a heavy disk 13, of a size tightly to tit and iill the bottom of the cavity 2, and a bushing I4, here shown integral with the disk 13, depending from the disk 13, and extending into, but not .through the aperture 7. The bushing 14 is provided with internal threads 15.

Removably mounted in the bushing 14 is the spike 16 shown in FIGURE 3. The spike I5 is rnade up of a point 17, a squared shank 18, a collar I9, and a threaded stud 20.

The `length of the stud, depthV of the bushing socket, thickness of cup bottom wall, and radial extent of the disk 13 .and collar 19 are such that, when the spike is turned up tight, the bottom wall 6 is compressed between the disk 13 and collar I9.

In FIGURE 2, an insert 22 is shown as molded into the `cup l1. Accordingly, in this embodiment, a disk 23 is buried in the bottom wall 6, with a relatively thin section 26 between the top of the disk 23 and the bottom surface of the cavity 2. In can be seen, that in this instance, an aperture 27 in the bottom `wall 6, does not extend entirely through the bottom 'wall into the cavity 2, but lopens through the lower surface of the bottom wall.

In the embodiment 'shown in FIGURE 5, the cup 1 is identical with the cup of the embodiment shown in FIG- URE 4. However, an insert 32 is formed in the shape of a cup, with a heavy bottom defined by a disk 33 and a cylindrical side wall 36, shown here as integral with the bottom disk 33. A bushing 34 with internal threads 35, depends, like .the bushing of the embodiment of FIGURE 4, from the disk 33, with which it is integral. While the area of the disk in the first two embodiments shown and described, is suicient to produce, with the ilat bottom of the crutch, a stable, rigid spike arrangement, itis possible, especially as the cup 41 ages, that side pressure of the crutch with respect .to the spike, might produce some rocking, :although this is unlikely. However, with the embodiment shown in FIGURE 5, in which the crutch tip tits into the socket provided by the wall 36 and bottom 33 of the insert, the possi-bility of such rocking is virtually eliminated.

Still another embodiment is shown in FIGURE 7. In this embodiment, as in the embodiment shown in FIG- URE 2, an insert is imbedded within the cup. In this embodiment, an insert 42 of the same general character as the insert 32, but somewhat larger, is imbedded in the walls of the cup.

In FIGURE 6, an embodiment of tip of this invention is shown, in which .the end ofthe crutch is modied so as to give even greater rigidity, as between the crutch and the spike, than is obtained in the previously described embodiments. ThisA latter embodiment is particularly adapted to use with thin canes and the like, because the insert can be made smaller than inserts shown in the other embodimentaand still accomplish the desired result. In this embodiment, the cup 1 and the insent 32 can be the same, structurally as, though they may be made smaller than the cup and insert of the embodiment shown in FIG- URE 5. A cane 50 `has a reduced end portion 51, providing an annular shoulder 52. The reduced end portion 51 fits closely within the socket defined 'by the wall 36 of the insert 32, and the fiat bottom of the cane and the shoulder 52 bear respectively on the upper surfacesV of the disk 33 and the wall 36.

In FIGURES 8 and 9, diierent embodiments of spike and spike coupling are illustrated. In FIGURE 9 a threepronged spike is shown. For convenience in manufacturing, it is shown as made in two parts. In the embodiment shown in FIGURE 9, a shank 91, with a threaded upper section 92, is provided with a slotted head 93. Between lthe :head 93 and the threaded section 92, is a collar 94, integral with `the shank. A plate 95, from which prongs 96 depend, has a central hole 97, smaller in diameter than the head 93, and lugs 98, clamping the head 93. A screw driver or the like can thus be used to tighten the spike.

In FIGURE 8 is shown an example of a bayonet type coupling, in which the bushing socket is provided with a channel 81, and the spike stud, with a pin 82 projecting radially, proportioned .to tit in the keyhole olset in the lvchannel in the usual manner. In the bayonet type coupling, the resilience of the material compressed between the collar of the spike and the disk, serves to maintain the pin in the keyhole portion of the channel, in mounted position.

It can be seen that in bayonet type, or even in screw type couplings, the male and Ifemale elements may be reversed, i.e., the bushing may provide the male element and the spike, the female. However, the embodiments shown are the preferred embodiments,.because they are structurally stronger.

The spike of the embodiments shown in FIGURES 2, 3 rand 8, the preferred embodiments, can be mounted and removed with the aid of a roller skate key or a small wrench. The spike shown in FIGURE 9 can be provided with a non-circular shank part, or the plate from which the prongs depend may be utilized to tighten the spike and remove it.

Having thus described the invention, what is claimed and desired to tbe secured by Letters Patent is:

1. A crutch tip adapted to fit the end of a crutch, said tip comprising a cup, of resilient material, of a size snugly d frictionally to engage the said crutch end, said cup having a central axially directed aperture in its bottom deiining wall; an insert mounted in said cup, said insert having a crutch-bottom-bearing disk of a size at least co-extensive with the bottom of the .crutch and positioned below the said bottom of the crutch when the crutch end is inserted in said cup, said disk carrying a depending bushing extendling into the said aperture and provided with coupling means; and a spike member having a radially-extending collar of a size to engage a substantial area of cup-bottom wall whenY the spike member is mounted and having spike coupling means complementary to the bushing coupling means, and so proportioned as to bring the said collar into engagement with the bottom wall and to compress a portion of said bottom wall between the collar and insert disk when the spike member is tightened, whereby the spike member is removably mountedV on said bushing.

2. The tip of claim l wherein said axially-directed aperture extends entirely through the bottom defining wall of said cup, and said disk is mounted within the cavity in said cup and is of a size to till the bottom of the cup cavity.

3. The tip of claim l wherein the insert disk is buried in the bottom wall of the cup.

4. The tip of claim 1, said insert having a cylindrical Wall on said disk, said wall extending toward but short of the mouth of the cup.

5. The tip of claim 4 wherein both the insert disk and cylindrical wall are buried in the wall of the cup.

6. The tip of claim 4 wherein the insert disk and cylindrical wall are within the cavity of the cup.

7. The tip of claim 1 wherein the spike member is provided with a pointed lower end and a non-,circular keyreceiving shank.

8. The tip of claim 1 wherein the bushing is a hollow cylinder, open at its lower end, the bushing coupling means are internal threads on the said cylinder, and the spike coupling means are external threads on a stud forming part of said spike.

9. The tip of claim 1 wherein the bushing and spike coupling means are complementary bayonet type couplings.

References Cited by the Examiner UNITED STATES PATENTS 281,245 7/83 Degenhart 13S-45 332,684 12/85 Tuttle 135-54 1,158,943 11/15 Louden 135-55 1,886,112 11/32 Luarde 45-137 X FOREIGN PATENTS 133,104 5/ 33 Austria. 826,186 12/51 Germany.

HARRISON R. MOSELEY, Primary Examiner. DONLEY I. STOCKING, Examiner. 

1. A CRUTCH TIP ADAPTED TO FIT THE END OF A CRUTCH, SAID TIP COMPRISING A CUP, OF RESILIENT MATERIAL, OF A SIZE SNUGLY FRICTIONALLY TO ENGAGE THE SAID CRUTCH END, SAID CUP HAVING A CENTRAL AXIALLY DIRECTED APERTURE IN ITS BOTTOM DEFINING WALL; AN INSERT MOUNTED IN SAID CUP, SAID INSERT HAVING A CRUTCH-BOTTOM-BEARING DISK OF A SIZE AT LEAST CO-EXTENSIVE WITH THE BOTTOM OF THE CRUTCH AND POSITIONED BELOW THE SAID BOTTOM OF THE CRUTCH WHEN THE CRUTCH END IS INSERTED IN SAID CUP, SAID DISK CARRYING A DEPENDING BUSHING EXTENDING INTO THE SAID APERTURE AND PROVIDED WITH COUPLING MEANS; AND A SPIKE MEMBER HAVING A RADIALLY-EXTENDING COLLAR OF A SIZE TO ENGAGE A SUBSTANTIAL AREA OF CUP-BOTTOM WALL WHEN THE SPIKE MEMBER IS MOUNTED AND HAVING SPIKE COUPLING MEANS COMPLEMENTARY TO THE BUSHING COUPLING MEANS, AND SO PROPORTIONED AS TO BRING THE SAID COLLAR INTO ENGAGAMENT WITH THE BOTTOM WALL AND TO COMPRESS A PORTION OF SAID BOTTOM WALL BETWEEN THE COLLAR AND INSERT DISK WHEN THE SPIKE MEMBER IS TIGHTENED, WHEREBY THE SPIKE MEMBER IS REMOVABLY MOUNTED ON SAID BUSHING. 